China on Thursday criticized the recent U.S. decision to pull out of a global postal treaty in a further escalation of President Donald Trump's confrontation with China over trade issues.

The White House announced Wednesday that Washington is preparing to withdraw from the Universal Postal Union treaty, accusing it of benefiting China and disadvantaging the United States in its treatment of shipping rates.

The postal union "has played a positive role in bringing countries closer to each other and promoting trade facilitation," Chinese Foreign Ministry spokesman Lu Kang said at a press briefing.

(Lu Kang)

"We regret the United States has decided to pull out of the Universal Postal Union," Lu said, adding, "We have always advocated and actively maintained multilateralism as well as actively taken part in and supported the work of the Universal Postal Union."

The treaty sets rates that national postal services charge to deliver mail and small packages from other countries. Poor and developing nations are assessed lower rates than wealthier countries, a benefit to Chinese companies.

It takes a year to withdraw from the Switzerland-based Union Postal Union. During that time, the United States will try to renegotiate shipment rates, but if that fails Washington will formally withdraw from the treaty, White House Press Secretary Sarah Huckabee Sanders said in a statement.

Trump's decision to withdraw from the Universal Postal Union is likely to deal a another blow to U.S.-China trade relations, already severely strained by a series of tit-for-tat tariff increases on hundreds of billions of dollars of shipments in each direction.

Since Trump took office in January 2017, the United States has withdrawn from a number of major multilateral frameworks, such as the 2015 Iran nuclear deal and the Paris Agreement on climate change.